root@server:/usr/src/tvheadend# grep CFLAGS /usr/src/tvheadend/libav_static/libvorbis-1.3.4/Makefile
CFLAGS = -O20 -Wall -Wextra -ffast-math -D_REENTRANT -fsigned-char -Wdeclaration-after-statement  -DUSE_MEMORY_H
OGG_CFLAGS =
        $(MAKE) all CFLAGS="-g -Wall -Wextra -D_REENTRANT -D__NO_MATH_INLINES -fsigned-char"
        $(MAKE) all CFLAGS="-pg -g -O20 -ffast-math -D_REENTRANT -fsigned-char"
root@server:/usr/src/tvheadend# ls -la /usr/src/tvheadend/libav_static/build/ffmpeg/include/ogg
total 32
drwxr-xr-x 2 root root 4096 Nov 27 15:42 .
drwxr-xr-x 5 root root 4096 Nov 27 15:42 ..
-rw-r--r-- 1 root root  499 Nov 27 15:42 config_types.h
-rw-r--r-- 1 root root 8433 Nov 27 15:42 ogg.h
-rw-r--r-- 1 root root 4271 Nov 27 15:42 os_types.h
root@server:/usr/src/tvheadend#